Game toy device using remote-controlled traveling toy, remote-controlled traveling toy, and game board

ABSTRACT

The present invention provides a play toy system using a remote-controlled traveling toy, which enables the remote-controlled traveling toy to make a movement that is more unexpected than before, for play. The remote-controlled traveling toy  1  includes one front wheel  5  and two rear wheels  7  and  9.  The traveling toy is remotely controlled by remote control signals and is so constructed as to travel on a traveling surface of a play board. The diameter sizes of the two rear wheels  7  and  9  are different. With one front wheel  5  and two rear wheels  7, 9  having a different diameter, the remote-controlled traveling toy  1  can move most unexpectedly that anyone has ever experienced, according to the state of the traveling surface of the play board.

TECHNICAL FIELD

The present invention relates to a play toy system using aremote-controlled traveling toy, a remote-controlled traveling toy, anda play board.

BACKGROUND ART

There have been hitherto known play toy systems played by causingremote-controllable traveling toys to compete with each other. JapanesePatent Application Laid-Open Publication No. 000962/2002 discloses aplay toy system played by making remote-controllable top toys travel onthe travel surface of a play board and then flipping the top toy of anopponent out of the play board or knocking down the top toy of theopponent. Japanese Utility Model Registration Publication No. 3092080discloses an example of a play board for top toys, provided with aplurality of concave portions in the central portion thereof forreceiving magnets.

The players' interest cannot be enhanced simply by causing theremote-controlled traveling toys to compete with each other as in theprior art, because the traveling toy does not make an unexpectedmovement. In the case of the play toy system like the one described inJapanese Patent Application Laid-Open Publication No. 000962/2002 inwhich the traveling toy is the top toy which turns on a pivot, in orderto cause the top toy to make the unexpected movement, it is necessary touse a permanent magnet or the like to change the course of the top toy,as on the play board disclosed in Japanese Utility Model RegistrationNo. 3092080. Alternatively, it is necessary to use a play board providedwith a special equipment such as a rotating board, like the play boarddisclosed in Japanese Utility Model Registration No. 3082469. Further,with the top toy, a sudden increase or decrease of the speed of thetraveling toy cannot be attained, so that it is difficult to obtain afeeling of speed.

Accordingly, an object of the present invention is to provide a play toysystem using a remote-controlled traveling toy which enables theremote-controlled traveling toy to make a movement that is moreunexpected than before, for play.

Another object of the present invention is to provide a play toy systemusing a remote-controlled traveling toy, in which the remote-controlledtraveling toy is difficult to be tumbled or turned over and can beplayed with stability.

Yet, another object of the present invention is to provide a play toysystem using a remote-controlled traveling toy that can be controlled toa sufficient degree even if a speed thereof is increased.

Still another object of the present invention is to provide a play boardand a play toy system using a remote-controlled traveling toy thatenables the remote-controlled traveling toy to make an unexpectedmovement to a sufficient degree just by increasing or decreasing a speedthereof.

DISCLOSURE OF THE INVENTION

A play toy system using a remote-controlled traveling toy according tothe present invention includes a remote control device for outputting aremote control signal, a remote-controlled traveling toy including onefront wheel, two rear wheels, and an electric motor remote controlled bythe remote control signal, and a play board having a travel surface onwhich the remote-controlled traveling toy travels. In the presentinvention, the diameter sizes of the two rear wheels of theremote-controlled traveling toy are made to be different. When a singlefront wheel is used with the diameter sizes of the rear wheels made tobe different, an unexpected movement that has not been experiencedbefore can be made by the remote-controlled traveling toy, according tothe state of the travel surface. For this reason, compared with a mereremote control, a much unexpected movement can be made by theremote-controlled traveling toy, for play, even if control can beexercised. Especially if this unexpectedness is actively used not onlywhen competing with the remote-controlled traveling toy of an opponentbut also when escaping from the toy of the opponent, a thrilling playcan be experienced.

Since the remote-controlled traveling toy makes an unexpected movement,fine control rather becomes an obstacle to speeding up as well as acause of reducing controllability. Thus, as the remote control device,the simple one is suitable that includes a switch to be operated foroutputting a signal for rotating the electric motor at a normal speedand an acceleration switch to be operated for outputting an accelerationsignal for rotating the electric motor at a speed faster than the normalspeed. When such the simple remote control device is employed, whatangle is set for the front wheel before the start of a play greatlyaffects subsequent control. Thus, setting the angle of the front wheelalso becomes part of the play, so that the interest of players can bemore enhanced.

When the diameter sizes of the two rear wheels are made to be different,the body of the remote-controlled traveling toy becomes inclined. Thus,depending on the angle of traveling, tumbling or turning over willreadily occur. Thus, preferably, in the body, one or more batteriesconnected to the electric motor are juxtaposedly arranged so thatlongitudinal axes thereof extend in the same direction as a direction inwhich the two rear wheels are arranged. In other words, preferably, thebatteries are arranged so that the longitudinal axes thereof extend indirections that cross the center line of the body of the traveling toyextends in the longitudinal direction of the body. With thisarrangement, not only the center of gravity becomes lower but also astable operation with respect to the lateral movement of the body can beobtained. Accordingly, even when inclination of the travel surface ofthe play board is sharp or complicated, tumbling will not readily occur,so that unexpected yet stable traveling can be obtained. Incidentally,when the electric motor is-arranged between the two rear wheels and theone or more batteries are arranged between the electric motor and thefront wheel, more stable traveling can be obtained.

The angle setting of the front wheel of the remote-controlled travelingtoy can be changed, and the wheel sections of the front wheel and therear wheels are so formed that a dynamic friction resistance between theplay board and the front wheel becomes smaller than dynamic frictionresistances between the rear wheels and the play board. When such theplay toy system is used, the movement of the remote-controlled travelingtoy can be made to be complicated, so that a more unexpected movementcan be implemented. Incidentally, when the dynamic friction resistancebetween the front wheel and the play board is too small, theremote-controlled traveling toy is apt to slip during traveling, so thatthe controllability of the remote-controlled traveling toy is reduced.Thus, the wheel section of the front wheel is formed of an ethylenepolymer including high-density polyethylene and low-densitypolyethylene. With this arrangement, due to the presence of thelow-density polyethylene, the surface roughness of the front wheel ofthe remote-controlled traveling toy becomes coarse. Thus, the dynamicfriction resistance of the front wheel can be increased more than in thecase where no high-density polyethylene is included, so that thecontrollability of the remote-controlled traveling toy can bemaintained. Incidentally, as a result of study by the inventor, it wasfound that if the low-density polyethylene accounts for 30 weightpercents or less of the ethylene polymer, the controllability of theremote-controlled traveling toy could be maintained most effectively.

In principle, any board may be used as the play board. However, it ispreferable that the travel surface of the play board as well is sodesigned as to take advantage of the difference in the diameters of therear wheels and obtain more unexpected traveling. When the travelsurface is continuous in a circumferential direction and is shaped sothat a height thereof from an installation surface is decreasing towarda central portion thereof, for example, a concave section is formed thathas a size capable of fully receiving the front wheel and/or the rearwheels and a depth allowing the remote-controlled traveling toy to getout of there by itself is formed. Depending on the size and depth of theconcave section and the speed of the remote-controlled traveling toy,the remote-controlled traveling toy falls into a state in which it isincapable of traveling or incapable of getting out of the concavesection. In other words, this is when the front wheel and all of therear wheels have fallen into the concave section and the speed of theremote-controlled traveling toy cannot be increased to a necessary andsufficient speed or when the body or an exterior attached to the body iscaught by the inner wall of the concave section and advancement cannotbe made with part or all of the wheels fallen into the concave section.When such the concave portion is formed in the central portion and oneof the rear wheels has fallen into the concave section, theremote-controlled traveling toy may abruptly make a reversed movement. Amore unexpected movement can be thereby given to the remote-controlledtraveling toy. Further, when the state, in which the traveling toy isincapable of getting out from the concave section, is defined as alosing condition of the competition play, the play will not becomeboring. Unlike a competition play which involves just escaping around,the play will become more interesting because a fall into the concavesection occurs during an escape around a lower area.

Incidentally, the study by the inventor has found that when an anglebetween the inner periphery surface of the concave section and theinstallation surface was set in the angle range of 93±1°, it wasprobable that an unexpected movement would be generated when one of therear wheels fell into the concave section.

It was also found that when the main portion of the travel surface wasconstituted by a first inclined surface adjacent to the concave sectionand having a first radius of curvature and a second inclined surfacecontinuous with the outside of the first inclined surface and having asecond radius of curvature close to infinity and the angle of the secondinclined surface from the installation surface was set in the anglerange of 32.2° to 42.2°, an unexpected movement could be obtained. Theunexpected movement includes the one in which the remote-controlledtraveling toy having different diameters of the read wheels abruptlyascends upward to the top of the second inclined surface upon gettinginto the first inclined surface. Accordingly, from a technicalviewpoint, these radiuses of curvature and the angle range havenoticeable effects.

Further, the effect of changing the diameter sizes of the two rearwheels of the remote-controlled traveling toy can be made to be moreoutstanding when the travel surface is constituted by a first inclinedsurface adjacent to the concave section and having a first radius ofcurvature, a second inclined surface continuous with the outside of thefirst inclined surface and having a second radius of curvature close toinfinity, a third inclined surface continuous with the outside of thesecond inclined surface and having a third radius of curvature smallerthan the first radius of curvature, and a fourth inclined surfacecontinuous with the outside of the third inclined surface and having afourth radius of curvature smaller than the third radius of curvature,when width sizes are set to become smaller in the order of the secondinclined surface, first inclined surface, third inclined surface, andfourth inclined surface, and when the angle of the second inclinedsurface from the installation surface is set in the angle range of 32.2°to 42.2°.

Then, when an angle between the third inclined surface and theinstallation surface is set in the angle range of 48±2°, when an anglebetween the fourth inclined surface and the installation surface is setin the angle range of 89±1°, or when substantially a horizontal surfaceis provided outside the fourth inclined surface, an unexpected orunpredictable movement can be made in each case by the remote-controlledtraveling toy. Incidentally, a combination of these angle ranges may bechanged as necessary according to the condition of the wheels of theremote-controlled traveling toy and the like. The remote-controlledtraveling toy and the play board used in the present invention inthemselves have technically excellent features. Though they have asimple configuration with small number of parts, they can be amusinglyplayed with both by children and adults.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1(A) through 1(F) are a plan view, a bottom view, a front view, arear view, a left side view, and a right side view of aremote-controlled traveling toy according to an embodiment of thepresent invention, suitable for use in a play toy system using aremote-controlled traveling toy of the present invention;

FIG. 2 is an exploded perspective view used for explaining attachment ofexterior parts;

FIG. 3 is a bottom view of the remote-controlled traveling toy with abattery cover thereof removed;

FIG. 4 is a perspective view showing an outward appearance of an exampleof a remote control device used in this embodiment;

FIGS. 5(A) through 5(C) are perspective views showing outwardappearances of an example of a play board used in this embodiment;

FIG. 6(A) is a sectional view through a VIA-VIA line in FIG. 5(C), andFIG. 6(B) is a diagram showing details of an enlarged sectional view ofa half part of the play board;

FIG. 7 is a diagram showing a state in which the remote-controlledtraveling toys in this embodiment are placed on the travel surface ofthe play board; and

FIGS. 8(A) and 8(B) are diagrams used for explaining examples of amethod of playing with the play toy system using the remote-controlledtraveling toy in this embodiment, respectively.

BEST MODE FOR CARRYING OUT THE INVENTION

An example of an embodiment of the present invention will be describedbelow in detail with reference to the drawings.

FIGS. 1(A) through 1(F) are a plan view, a bottom view, a front view, arear view, a left side view, and a right side view of aremote-controlled traveling toy 1 according to an embodiment of thepresent invention, suitable for use in a play toy system using aremote-controlled traveling toy of the present invention. Thisremote-controlled traveling toy 1 includes one front wheel 5 to thefront of a body 3 and two rear wheels 7 and 9 to the rear of the body 3.The diameter of the front wheel 5 is the smallest of the three wheels.Then, the diameter sizes of the two rear wheels 7 and 9 are different.When the diameter size of the rear wheel 9 is set to 1, the diametersize of the rear wheel 9 and the diameter size of the rear wheel 7 arein the relation of approximately 1:0.8. With regard to the geometriesand structure of the remote-controlled traveling toy in this embodiment,when the diameter of the rear wheel having the larger diameter size isset to 1, it is preferable that the ratio of the diameter sizes of therear wheels is set in the range of 1:0.738 to 1:0.775. If the ratio isset within this range, a difference in the diameter sizes does notbecome an obstacle to traveling, and moreover, an unexpected travelingcharacteristic can be obtained. Incidentally, the preferable ratio isnot limited to the above-mentioned example, and is changed depending ona combination of the shape and size of the body of the traveling toy,the material of the rear wheels, the size of the play board, and theangle and material of an inclined surface and the like.

An angle setting of front wheel supporting arms 11 by which the frontwheel 5 is supported can be changed within a predetermined angle rangewith respect to a rotation center 13. In order to keep the angle settingunchanged during traveling, a click mechanism may be provided in arotation mechanism thereof.

Six attached sections 15 through 25 for attaching exterior parts theretoare provided on the top surface and the rear surface of the body 3. Fourtypes of exterior parts 27 through 33 shown in FIG. 2 can be attached tothese attached sections 15 through 25. It is not essential to attachthese exterior parts 27 through 33. They may be attached according topreference of the player. Exterior parts having shapes other than thoseshown in FIG. 2 may be of course attached.

FIG. 3 shows a bottom view of the remote-controlled traveling toy 1 witha battery cover 35 removed. In this remote-controlled traveling toy, anelectric motor is arranged in the rear area of the body 3 locatedbetween the two rear wheels 7 and 9. Then, two batteries 37 are arrangedin a front area 3B between the electric motor and the front wheel.Incidentally, circuit boards for a wireless communication circuit andthe control circuit of the electric motor may be arranged in either of arear area 3A and the front area 3B. In this example, the circuit boardsare arranged in the rear area 3A. The two batteries 37 are juxtaposedlyarranged so that the longitudinal axes thereof extend in the samedirection as the direction in which the two rear wheels 7 and 9 arearranged, or the longitudinal axes thereof cross the center line of thebody of the traveling toy extending in the longitudinal direction of thebody. Specifically, the batteries 37 are so arranged that the axes ofthe rear wheels 7 and 9 and the longitudinal axes of the batteries 37become parallel. With this arrangement, not only the center of gravitybecomes lower but also a stable operation with respect to the lateralmovement of the body can be obtained. Accordingly, even when inclinationof the travel surface of the play board is sharp or complicated,tumbling will not readily occur, so that unexpected yet stable travelingcan be obtained.

The angle of the front wheel 5 of the remote-controlled traveling toy 1is adjusted so as to enable angle setting to be changed. Specifically,the front wheel 5 is fixed to the attached section 15 so as to berotatable within the angle range of ±45 degrees with respect to the axisline in the longitudinal direction of the remote-controlled travelingtoy 1. Then, the dynamic friction resistance between the front wheel 5and the play board is formed to be smaller than the dynamic frictionresistances between the rear wheel 7 and the play board and between therear wheel 9 and the play board. In this embodiment, the wheel sectionof the front wheel 5 is formed of an ethylene polymer, and the rearwheels 7 and 9 are formed of a rubber-based material. With thisarrangement, movements of the remote-controlled traveling toy can bemade to be complicated, so that a more unexpected movement can beimplemented. In this embodiment, the wheel section of the front wheel 5is formed of an ethylene polymer including low-density polyethylene andhigh-density polyethylene, and specifically, the low-densitypolyethylene accounts for 30 weight percents or less of the ethylenepolymer. Due to the presence of the low-density polyethylene, thesurface roughness of the wheel section of the front wheel 5 becomescoarse. Thus, the dynamic friction resistance of the front wheel can beincreased more than in the case where no low-density polyethylene isincluded, so that the controllability of the remote-controlled travelingtoy can be maintained. Incidentally, in order to maintain thecontrollability of the remote-controlled traveling toy most effectively,in this embodiment, the ethylene polymer in which the low-densitypolyethylene and the high-density polyethylene are compounded at ratesof 20 weight percents and 80 weight percents, respectively is employedas the material of the wheel section of the front wheel 5.

FIG. 4 is a perspective view showing an outward appearance of an exampleof a remote control device 39 used in this embodiment. This remotecontrol device 39 has a simple configuration equipped with only twocontrol switches of a switch SW1 to be operated for outputting a signalfor rotating the electric motor at a normal speed and an accelerationswitch SW2 to be operated for outputting an acceleration signal forrotating the electric motor at a speed faster than the normal speed.When the acceleration switch SW2 is depressed, the speed is set toseveral times the speed when the switch SW1 is depressed. When theswitch SW1 is kept on being depressed, the toy travels substantially ata certain speed. When the switch SW1 is released, power distribution tothe electric motor is stopped, so that the speed is decreased. Then,when the acceleration switch SW2 is depressed with the switch SW1 beingdepressed, abrupt acceleration is performed at a predeterminedacceleration from the normal rotational speed. A command (theacceleration signal) from the acceleration switch SW2 may be transmittedonly while the switch SW1 is depressed. However, even when theacceleration switch SW2 alone is depressed while the switch SW1 is notdepressed, the acceleration signal may be transmitted. Either ofwireless remote control or infrared remote control may be exercised.When such the simple remote control device 39 is employed, what angle isset for the front wheel 5 before the start of a play greatly affectslater control. Thus, setting the angle of the front wheel 5 also becomespart of the play.

FIGS. 5(A) through 5(C) are a perspective view, a front view, and a planview of a play board 41 used in this embodiment. Then, FIG. 6(A) is asectional view through a VIA-VIA line in FIG. 5(C). FIG. 6(B) showsdetails of a sectional view showing a half part of the play board 41. Inthis play board 41, a travel surface 42 is shaped to be continuous in acircumferential direction thereof and have its height from aninstallation surface 40 decreasing toward the central portion thereof.Then, in the central portion thereof is formed a concave section 43 witha size fully receiving the remote-controlled traveling toy 1 and with adepth allowing the remote-controlled traveling toy 1 to get out of thereby itself. This concave section 43 may be the one with the size fullyreceiving the front wheel 5 and/or the rear wheels 7 and 9 and with thedepth from which the remote-controlled traveling toy 1 can get out byitself, and is not limited to this example. When such the concavesection 43 is formed in the central portion and one of the rear wheels 7and 9 falls into the concave section 43, the remote-controlled travelingtoy 1 may abruptly make a reversed movement, so that a more unexpectedmovement can be given to the remote-controlled traveling toy 1. Further,depending on the size and depth of the concave section 43 and the speedof the remote-controlled traveling toy 1, the remote-controlledtraveling toy 1 falls into a state in which the toy is incapable oftraveling or incapable of getting out of the concave section 43. Inother words, this is when the front wheel 5 and all of the rear wheels 7and 9 have fallen into the concave section 43 and the speed of theremote-controlled traveling toy 1 cannot be increased to a necessary andsufficient speed or when the body 3 or an exterior attached to the body3 is caught by the inner wall of the concave section and advancementcannot be made with part or all of the wheels 5, 7 and 9 fallen into theconcave section 43.

Assume that an angle θ₀ between the inner periphery surface of theconcave section 43 and the installation surface 40 is set in the anglerange of 93±1° as shown in FIG. 6(B). Then, it is probable that anunexpected movement will be generated when one of the rear wheels 7 and9 has fallen into the concave section 43.

Further, the travel surface 42 includes a first inclined surface 42Aadjacent to the concave section 43 and having a first radius ofcurvature R1 (118.5), a second inclined surface 42B continuous with theoutside of the first inclined surface 42A and having a second radius ofcurvature close to infinity, a third inclined surface 42C continuouswith the outside of the second inclined surface 42B and having a thirdradius of curvature R2 (98.5) smaller than the first radius ofcurvature, and a fourth inclined surface 42D continuous with the outsideof the third inclined surface 42C and having a fourth radius ofcurvature R3 (18.5) smaller than the third radius of curvature. Then, inthis embodiment, width sizes (or the sizes in the slope ascendingdirection) of the first, second, third, and fourth inclined surfaces areset to become smaller in the order of the second inclined surface 42B,first inclined surface 42A, third inclined surface 42C, and fourthinclined surface 42D. Then, an angle 6 of the second inclined surface42B from the installation surface 40 is set in the angle range of 32.2°to 42.2°. Specifically, this angle is set to 37.2°.

Preferably, an angle θ1 between the third inclined surface 42C and theinstallation surface 40 is set in the angle range of 48±2°, and an angleθ2 between the fourth inclined surface 42D and the installation surface40 is set in the angle range of 89±1°. Further, in this embodiment,substantially a horizontal surface 42E is provided outside the fourthinclined surface 42D.

When the travel surface 42 is determined as described above, anunexpected or unpredictable movement can be made by theremote-controlled traveling toy 1.

FIG. 7 shows a state in which the remote-controlled traveling toys 1 inthis embodiment are placed on the travel surface 42 of the play board41. Respective remote-controlled traveling toys 1A to 1C are inclinedrelative to the inclined surface differently. These inclinations givethe remote-controlled traveling toys an unexpected movement.

When playing with the play toy system in this embodiment, a case wherethe remote-controlled traveling toy of an opponent is hit from the sideor behind and pushed out of the play board 41, as shown in FIG. 8(A),for example, may be defined as a victory. Alternatively, a case wherethe remote-controlled traveling toy of the opponent is knocked off intothe concave section 43 in the center of the travel surface and cannotget out of the concave section 43 as shown in FIG. 8(B) may be definedas the victory. A victory criterion may be defined arbitrarily.

Incidentally, in this embodiment, the electric motor, front wheel, rearwheel, and exterior parts are attached so as to enable replacement.Accordingly, if these parts are replaced for play according to astrategy, the interest of the players is more enhanced.

In the embodiment described above, the concave section 43 with acircular sectional shape was employed. The sectional shape of theconcave section 43 is not limited to the circular one, and the one withan oval sectional shape or other sectional shape may be of courseemployed.

The present invention is configured based on a technical concept inwhich the diameters of some wheels among a plurality of wheels of thetraveling toy may be different, and accordingly the body of thetraveling toy may be inclined so that unexpected traveling is obtained.This technical concept can be naturally applied to traveling toys withfour wheels or more wheels as well as traveling toys with three wheels.

INDUSTRIAL APPLICABILITY

When the diameter sizes of the two rear wheels of the remote-controlledtraveling toy are made to be different and only one wheel is used as thefront wheel, as in the present invention, the remote-controlledtraveling toy can be caused to make an unexpected movement that has notbeen experienced before, depending on the state of the travel surface.Thus, compared with a mere remote control, the player can enjoy playingwith the remote-controlled traveling toy which can make the unexpectedmovement even though the remote-controlled traveling toy can becontrolled. Especially if this unexpectedness is actively used not onlywhen competing with the remote-controlled traveling toy of an opponentbut also when escaping from the toy of the opponent, the advantage ofexperiencing a thrilling play can be obtained.

Further, by employing as the remote control device the simple remotecontrol device equipped with the switch to be operated for outputting asignal for rotating the electric motor at a normal speed and theacceleration switch to be operated for outputting an acceleration signalfor rotating the electric motor at a speed faster than the normal speed,an advantage can be obtained that controllability will be scarcelyreduced even if the remote-controlled traveling toy makes an unexpectedmovement and even if the remote-controlled traveling toy achievesspeeding up.

Further, when the electric motor and one or more batteries connected tothe electric motor are mounted onto the body of the traveling toy andthe one or more batteries are juxtaposedly arranged so that thelongitudinal axes thereof cross the central line of the body thatextends in the longitudinal direction of the body, not only the centerof gravity is lowered, but also a stable operation with respect to thelateral movement of the body can be obtained. Accordingly, even wheninclination of the travel surface of the play board is steep orcomplicated, another advantage is obtained that tumbling will not occurreadily and unexpected yet stable traveling can be obtained.

Further, when the front wheel of the remote-controlled traveling toy isformed of polyolefin including at least low-density polyethylene, thesurface roughness of the front wheel of the remote-controlled travelingtoy becomes coarse. Thus, the friction coefficient of the front wheel ismore increased than in a case where no low-density polyethylene isincluded. Thus, the controllability of the remote-controlled travelingtoy can be maintained.

1. A play toy system using a remote-controlled traveling toy,comprising: a remote control device for outputting a remote controlsignal; a remote-controlled traveling three-wheeled toy having only onefront wheel, only two rear wheels, and an electric motor remotecontrolled by said remote control signal; and a play board having atravel surface on which said remote-controlled traveling toy travels;wherein diameter sizes of said two rear wheels of said remote-controlledtraveling toy are different; wherein said play board is shaped so thatsaid travel surface is continuous in a circumferential direction thereofand a height thereof from an installation surface is decreasing toward acentral portion thereof; and in said central portion thereof is formed aconcave section with a size capable of fully receiving said front wheeland/or said rear wheels and a depth allowing said remote-controlledtraveling toy to get out of there by itself.
 2. The play toy systemusing a remote-controlled traveling toy according to claim 1, wherein anangle between an inner periphery surface of said concave section andsaid installation surface is set to an angle range of 93±1°.
 3. The playtoy system using a remote-controlled traveling toy according to claim 1,wherein a main portion of said travel surface comprises a first inclinedsurface adjacent to said concave section and having a first radius ofcurvature and a second inclined surface continuous with an outside ofsaid first inclined surface and having a second radius of curvatureclose to infinity; and an angle of said second inclined surface fromsaid installation surface is set in the angle range of 32.2° to 42.2°.4. The play toy system using a remote-controlled traveling toy accordingto claim 1, wherein said travel surface comprises a first inclinedsurface adjacent to said concave section and having a first radius ofcurvature, a second inclined surface continuous with an outside of saidfirst inclined surface and having a second radius of curvature close toinfinity, a third inclined surface continuous with an outside of saidsecond inclined surface and having a third radius of curvature smallerthan the first radius of curvature, and a fourth inclined surfacecontinuous with an outside of said third inclined surface and having afourth radius of curvature smaller than the third radius of curvature;width sizes of said first, second, third, and fourth inclined surfacesbecome smaller in an order of said second inclined surface, said firstinclined surface, said third inclined surface, and said fourth inclinedsurface; and an angle of said second inclined surface from saidinstallation surface is set in the angle range of 32.2° to 42.2°.
 5. Theplay toy system using a remote-controlled traveling toy according toclaim 4, wherein an angle between said third inclined surface and saidinstallation surface is set in an angle range of 48±2°; and an anglebetween said fourth inclined surface and said installation surface isset in an angle range of 89±1°.
 6. The play toy system using aremote-controlled traveling toy according to claim 5, wherein asubstantially horizontal surface is provided outside said fourthinclined surface.
 7. A play board having a travel surface on which aremote-controlled traveling three-wheeled toy travels, wherein said toyhas only one front wheel, only two rear wheels, and an electric motorremotely controlled by a remote control signal, said travel surface isshaped to be continuous in a circumferential direction thereof and havea height thereof from an installation surface is decreasing toward acentral portion thereof; and in said central portion thereof is formed aconcave section with a size capable of fully receiving said front wheeland/or said rear wheels and a depth allowing said remote-controlledtraveling toy to get out of there by itself.
 8. The play toy systemusing a remote-controlled traveling toy according to claim 2, wherein amain portion of said travel surface comprises a first inclined surfaceadjacent to said concave section and having a first radius of curvatureand a second inclined surface continuous with an outside of said firstinclined surface and having a second radius of curvature close toinfinity; and an angle of said second inclined surface from saidinstallation surface is set in the angle range of 32.2° to 42.20°. 9.The play toy system using a remote-controlled traveling toy according toclaim 2, wherein said travel surface comprises a first inclined surfaceadjacent to said concave section and having a first radius of curvature,a second inclined surface continuous with an outside of said firstinclined surface and having a second radius of curvature close toinfinity, a third inclined surface continuous with an outside of saidsecond inclined surface and having a third radius of curvature smallerthan the first radius of curvature, and a fourth inclined surfacecontinuous with an outside of said third inclined surface and having afourth radius of curvature smaller than the third radius of curvature;width sizes of said first, second, third, and fourth inclined surfacesbecome smaller in an order of said second inclined surface, said firstinclined surface, said third inclined surface, and said fourth inclinedsurface; and an angle of said second inclined surface from saidinstallation surface is set in the angle range of 32.2° to 42.2°.